This invention is generally directed to imaging members, and more specifically, the present invention is directed to multilayered photoconductive imaging members comprised of about 50 to about 70 crosslinked, for example from about 50 to about 70 percent crosslinked, which crosslinking is determined by nuclear magnetic resonance (NMR), photogenerating layer containing, for example, a photogenerating pigment or mixtures thereof and a thermally crosslinkable vinyl chloride copolymer, or a thermally crosslinkable vinyl chloride copolymer blend. Specific examples of the aforementioned crosslinkable components are vinyl chloride copolymers, such as a vinyl chloride/allyl glycidyl ether/hydroxypropyl methacrylate copolymer; crosslinkable vinyl chloride copolymer blends, such as a vinyl chloride/vinyl acetate/maleic acid and a vinyl chloride/vinyl acetate/allyl glycidyl ether copolymer blend with a weight ratio of, for example, about 80/20; a vinyl chloride/allyl glycidyl ether/hydroxypropyl methacrylate copolymer; a polymer blend of a vinyl chloride/vinyl acetate/maleic acid copolymer and a vinyl chloride/vinyl acetate/allyl glycidyl ether copolymer, and which components function primarily as a binder which crosslinks at high temperatures of, for example, from about 120° C. to about 300° C., and more specifically, from about 135° C. to about 160° C. resulting in excellent integrity of the charge generating layer, high adhesion characteristics between the photogenerating layer or charge generating layer, and other layers of the imaging member, such as the supporting substrate layer, the hole blocking layer. The hole blocking layer is preferably in contact with a supporting substrate, and more specifically, is situated between the supporting substrate and the photogenerating layer comprised, for example, of the photogenerating pigments of U.S. Pat. No. 5,482,811, the disclosure of which is totally incorporated herein by reference, especially Type V hydroxygallium phthalocyanine.
The imaging members of the present invention in embodiments exhibit excellent cyclic/environmental stability with little change in their photoinduced discharge curves (PIDC) after a number of charging/exposure cycles in varying environmental zones. The PIDC curves of the photoconductive imaging members were obtained with an electrical scanner set to obtain photoinduced discharge cycles, and sequenced at one charge-erase cycle followed by one charge-expose-erase cycle, wherein the light intensity is incrementally increased with cycling to produce a series of photoinduced discharge characteristic curves from which the photosensitivity and surface potentials at various exposure intensities are measured. Additional imaging members electrical characteristics can be obtained by a series of charge-erase cycles with incrementing surface potential to generate several voltage versus charge density curves, and wherein a scanner is equipped with a scorotron set to a constant voltage charging at various surface potentials. The devices or members are then tested with the exposure light intensity incrementally increased by means of regulating a series of neutral density filters; the exposure light source is a 780 nanometer light emitting diode. In embodiments the photoconductive imaging members of the present invention exhibit favorable photoinduced discharge curves, excellent adhesion characteristics, which are measured by a pull type adhesion test for the layers selected, strengthened interface connections between the layers, excellent hardness, low charge deficient spot (CDS) counts thus less small-spot print defects, which counts are measured by conducting a print test with two solid white and solid black documents; the solid white documents can be analyzed by scanning for spots that are less than about 0.5 millimeter in diameter; foreign contaminants which can generate large-spot print defects, and substantially no adverse changes in the imaging member performance over extended time periods. The aforementioned photoresponsive, or photoconductive imaging members can be negatively charged when the photogenerating layer is situated between the hole transport layer and the substrate.
Processes of imaging, especially xerographic imaging, and printing, including digital, are also encompassed by the present invention. More specifically, the layered photoconductive imaging members of the present invention can be selected for a number of different known imaging and printing processes including, for example, electrophotographic imaging processes, especially xerographic imaging and printing processes wherein charged latent images are rendered visible with toner compositions of an appropriate charge polarity. The imaging members as indicated herein are in embodiments sensitive in the wavelength region of, for example, from about 500 to about 900 nanometers, and in particular from about 650 to about 850 nanometers, thus diode lasers can be selected as the light source. Moreover, the imaging members of this invention can be selected for color xerographic applications.